1. Field of the Invention
This invention relates to liquid propellant guns utilizing a differential piston to provide continued or regenerative injection of propellant into the combustion chamber after initial ignition of propellant in the chamber.
2. Prior Art
Liquid propellant guns utilizing differential pistons to pump propellant into the combustion chamber during combustion are now well know. Early work is described in a Final Report of Nov. 19, 1953--Jan. 31, 1956 under contract DA-36-034-ORD-1504RD, Project TS1-47-8 by V. M. Barnes, Jr. et al which apparently in part corresponds to Jukes et al., U.S. Pat. No. 3,138,990 filed Oct. 9, 1961; in a report No. 17-2 of June 15, 1954 under contract NOrd-10448 by C. R. Foster el at; and in a Final Report of Sept. 1, 1957 under contract NOrd 16217, Task 1, by L. C. Elmore et al. Other patents of interest are J. W. Treat, Jr., U.S. Pat. No. 2,922,341, filed Nov. 7, 1955; E. J. Wilson, Jr. et al., U.S. Pat. No. 2,981,153, filed Nov. 14, 1952; C. M. Hudson, U.S. Pat. No. 2,986,072, filed Nov. 19, 1952; and E. J. Vass, et al., U.S. Pat. No. 3,690,255 filed Oct. 1, 1970.
An object of this invention is to provide an improved liquid propellant gun having a combustor assembly utilizing a differential piston wherein a uniform metered quantity of atomized propellant may be passed into the combustion chamber to serve as a primer without additional valves in said piston.
A second object of the invention is to avoid the complexity of providing a means for retaining propellant behind the piston during the filling operation by simply allowing said propellant to "leak" through the piston into the combustion chamber for purposes described under the first object of the invention.
A feature of this invention is the provision of a liquid propellant gun utilizing a differential piston having a plurality of bores through its head, which head divides the liquid propellant pumping chamber from the combustion chamber, and propellant supply means providing liquid propellant under fixed feed pressure into said pumping chamber, which propellant under pressure both advances the piston to enlarge the pumping chamber and to decrease the combustion chamber while increasing pressure in said combustion chamber and injects and atomizes a predetermined quantity of propellant through said bores from said pumping chamber into said combustion chamber to serve as a primer.